iCloud is the official iCloud app for Windows. This will allow you to download all the files you have stored there and upload new content to the Apple cloud.

From iCloud, you can automatically sync content and more from your computer.

Starting with iCloud Photos, you can sync all your images and videos in the cloud, including those only available on your PC. You can also create shared albums to which other users can add content.

iCloud Drive makes it easy to store all kinds of files, folders, and documents. In addition to being able to share them via link, you can copy them directly from Windows File Explorer to the cloud as if they were another folder, similar to how Microsoft integrates OneDrive into its operating system.

Another factor that can be synced is passwords. You can view them, add new ones, and sync them directly with your web browser via the iCloud Passwords extension.

Finally, other elements such as emails, contacts, calendars and bookmarks can also be synced. Install the Bookmarks extension to sync your bookmarks with iCloud.

So, if you are in the Apple ecosystem, you cannot stop iCloud downloads.